1. Field of the Invention
This invention relates to the handling of dough for baking, and more particularly concerns a method and apparatus for dispensing successive pieces of dough of constant weight.
2. Description of the Prior Art
Methods and apparatus for pumping, homogenizing and dividing dough into pieces of predetermined uniform weight for baking into bread loaves, buns, rolls and the like are disclosed in U.S. Pat. Nos. 4,960,601, 4,517,212; 4,449,908; 4,424,236; and 4,332,538. In general, such apparatus includes a hopper which receives dough, auger means for advancing the dough, metering means which control the advance of the dough, multiple nozzles which receive the metered dough, and cutting means which sever the continuously advancing dough into discrete pieces which fall onto an underlying moving belt. A homogenizing step is usually included, which may be accomplished by mixing means usually referred to as a "developer".
It is very important that each dough piece be as equal in weight to each other as possible. The uniformity of weight not only produces products of uniform quality but facilitates the automated handling and packaging of the baked products. Also, the weight of the dough is one of the most expensive cost elements in manufacturing baked goods, and control of the weight tolerances can reduce the need for excess dough. The production of dough pieces of uniform weight is known as scaling in the trade. In general, less than 2% deviation in weight is sought relative to a target weight.
Metering means such as cylinder-housed pistons have been employed to achieve improved scaling. However such devices require use of mineral oil which escapes as an undesirable atomized vapor of concern as a health hazard. Such devices also produce an undesirable high noise level. Although metering means, such as a positive displacement pump, has been employed to achieve uniform scaling, inaccuracies are experienced. This results from the fact that the metering pump dispenses a constant volume, but the dough has a non-uniform density because of gas-formation produced by the yeast content of the dough. Prior efforts to achieve greater uniformity of dough density have included degassing techniques and pressurization of the dough upstream of the volumetric metering means.
It has been found however, that dough can degrade in the dough-handling apparatus, the degree of degradation being increased by factors such as high pressure, the time duration of said pressure, and shearing forces at the surfaces of passages through which the dough travels. The degradation becomes apparent in the finished product in the form of swirl patterns and non-uniformity of texture along with discoloration and circular stratiform.
Equipment for processing the dough has generally involved hydraulically driven motors. Such motors permit leakage of hydraulic fluid onto the surfaces that contact the dough, and further produce high noise levels.
It is accordingly an object of the present invention to provide apparatus for pumping, homogenizing and dividing dough into successive pieces of uniform weight.
It is another object of this invention to provide apparatus as in the foregoing object which produces minimal degradation of the dough.
It is another object of the present invention to provide apparatus of the aforesaid nature having few moving components.
It is a still further object of this invention to provide apparatus of the aforesaid nature which an be easily dismantled to facilitate cleaning and repair.
It is yet another object of the present invention to provide a method, achievable by the aforesaid apparatus, for dispensing successive pieces of dough of uniform weight.
These and other beneficial objects and advantages will be apparent from the following description.